Image processing is a relatively new field which involves the capturing of a video image, or other sensory image, and provides the ability to modify the image in various ways before presenting the same to a viewer. Graphics modification may be carried out in a number of well-known manners, such as scaling the size of the image, rotating it about an axis, modifying its color characteristics, etc. It is customary to convert images, pictures or other sensory information, into a digital format for storage in a memory of an image processing system. The data can then be operated upon in accordance with conventional algorithms for modifying the image to produce the desired visual effects.
Traditionally, the processing of an image is initiated by converting light, sound, x-rays, or other sensory information into digital values, and storing the same in a computer memory. Each digital value, or group of values comprising a word, represents a picture element, i.e., pixel, which are arranged in a grid pattern covering the image space known as an image array or pixel map. The image stored in a frame buffer can then be subjected to a series of operations to present an enhanced version thereof on a video screen, or printed on a paper media.
Several shortcomings are inherent with conventional image processing techniques. First, the size of the image presented to the viewer is constrained to that which can be accommodated by the computer memory. A four kilobit by four kilobit size memory has been found by some persons to be the optimum to provide a picture with sufficient resolution. In other applications, a 512.times.512 pixel array may be optimal. While larger memories could accommodate correspondingly more pixel storage area for larger images, more processing time is needed to operate upon the pixels and present an enhanced image thereof on a display screen. Accordingly, the overall system response becomes slower due to the additional data required to be processed.
Computer graphics have become well developed for generating geometric representations, such as lines, circles, polygons and other more complicated figures. Such representations are generated with specific mathematical equations, and can be altered by the interaction with a keyboard, or the like, and a computer. A repertoire of mathematical equations is generally provided, along with techniques for altering the same, to provide enhanced or modified geometrical figures. Again, a graphic representation of an image is stored in digital form in a pixel array of the image computer memory. The computer operates on the pixel data in the video frame buffer to redraw or display the enhanced graphical image on a screen, or print the same on a paper media. In contrast with image processing where an existing image is captured and a representation thereof is stored in a data base, graphical images are generated within the computer itself and stored in a data base.
It can be seen from the foregoing that a need exists for a high speed image processing system which provides image enhancement and feature extraction capabilities, neither of which compromise the system response nor the resolution or quality of the image. There is an associated need for providing improved image enhancement techniques in the nature of increased contrast or expansion to cover a larger dynamic range to also enhance the image for viewing or further processing. A further need exists for an image computing system for extracting features of the image and evaluating the foregoing and comparing the same with other stored parameters or data.